Making reinforced fabrics

ABSTRACT

Between the creel rack and the embedding stage of a wirereinforced fabric making machine, particularly a machine made by Berstorff, is inserted a tensioning device for the wires which is common to many wires of each layer. The device as shown has a pair of spaced-apart, grooved, braked, rollers with their axes mutually positioned by swivelling link arms so that the rollers may be moved from condition in which the common plane of their axes is vertical (to facilitate threading of the generally horizontal wires when the machine is being set up) to one where the wires are made to execute an S bend round the rollers and thus drive them in common against the braking resistance.

O United States atent 1 91 1111 3,885,604

Rowland May 27, 1975 [54] MAKING REINFORCED FABRICS 3,223,126 12/1965 Zerbee 140/3 3,246,818 4/1966 Davis [75] Inventor: s w r g i f 3,386,679 6/1968 Foulon et al 226/195 e s am, ng an [73] Assignee: Avon Rubber Company Limited, Primary X inerLO ell A. Larson Melksham, Wiltshire, E l nd Attorney, Agent, or Firml(enyon & Kenyon Reilly 22 Filed: Apr. 5, 1974 [21] Appl. No.: 458,349 [57] ABSTRACT Between the creel rack and the embedding stage of a [30] Foreign Application Priority D t wire-reinforced fabric making machine, particularly a Apr. 9, 1973 United Kingdom 16945/73 machine made by Bersmrff is inserted a tensioning device for the wires which is common to many wires 52 US. Cl 140/3 0; 226/195; 242/153 of each The device as Show" has a P Of [51] Int. Cl B2lf 23/00 spaced'aPart grooved braked rollers with their a [58] Field of Search 140B 242/153 156 mutually positioned by swivelling link arms so that the 6 156/494. 226/195 rollers may be moved from condition in which the common plane of their axes is vertical (to facilitate [56] References Cited threading of the generally horizontal wires when the machine is being set up) to one where the wires are UNITED STATES PATENTS made to execute an S bend round the rollers and thus Z4 z fg/ drive them in common against the braking resistance. enyon 2,268,277 12/1941 Carter et a1 242/153 11 Claims, 5 Drawing Figures MAKING REINFORCED FABRICS FIELD OF THE INVENTION This invention is concerned with the making of metalreinforced fabrics such as are used particularly in radial-ply tyres.

BACKGROUND OF THE INVENTION A typical fabric includes a plurality of parallel spaced wire cords of which are embedded as reinforcement in an elastomer, usually by a calendering process.

Various machines are known for this manufacture, perhaps the best known being a machine of the type made by Berstorff in Germany, but problems are encountered in the feed of the reinforcing wires to the embedding process. Each layer of wires has to have each wire under substantially the same tension otherwise there will be irregularities in the material produced, and it will be rejected.

The reels are mounted in horizontal rows, one above the other, in a creel rack. There may be a large number of wires in any given layer and each wire derives from one reel. Reels are mounted one behind another in the rack, in each layer, and may also be mounted side by side.

To provide the desired tension, every single reel in the rack has been provided with its own friction brake or other form of brake. Usually this is a simple friction pad or strap. The pad acts as a friction disc brake. It is engaged to the end face of a reel and its braking effect is derived from the weight of the reel pressing it into engagement with a stationary pad (the axis of the reel is tilted to the horizontal). The braking effect is unpredictable and dependent on the weight of wire in the reel at any one time. The strap brake acts as a band brake over a cylinder extension engaged by the reel and is loaded by a deadweight. Any oil or grease on the strap, or interference with the deadweight will cause loss of braking effect. Quite apart from the capital cost of equipping every single reel position in the creel rack in this way (and there may be thousands of them), there is the operational problem that malfunction of any one out of the hundreds or possibly thousands of individual brakes may cause one wire to run slack, with consequent possible rejection of a whole or part of a batch.

SUMMARY OF THE INVENTION The present invention is concerned with a novel way of governing and rendering substantially equal the tension under which reinforcing wires of a layer pass from a creel stand to the embedding machine.

The invention tackles this problem providing common tensioning for the wires in a layer between where the wires leave their respective reels and where they go into the embedding machine. There may be but one tensioning arrangement for the whole of a layer, or a pair or more; but in any case a substantial number of wires in the layer are given a common braking away from their reels, so that they have a common tension. The wires are passed over and made to drive a tensioning arrangement of rollers which have a resistance to rotation, which may be either wholly due to radial bearing forces or due to such forces supplemented by a brake. The interaction between each wire and the roller is the same and thus the wires have a common treatment.

In a preferred form of the invention the tensioning arrangement includes a pair of spaced apart rollers rotatable about respective axes and each respectively having a friction brake for subjecting them to a resistance to rotation.

A preferred mounting for this pair of rollers includes a pivoting link between the shafts defining the axes about which the rollers respectively rotate whereby the common plane containing the two axes of the rollers may be brought, for example, for a vertical attitude through a horizontal attitude to one below the horizontal (when the wires in a generally horizontal direction from the creel rack to the embedding machine), and means for releasably locking the respective rollers in the attitude where the common plane of their two axes is below the horizontal so that the wires make a double bend round the rollers and will drive them in rotation.

In this way, when a machine is being set up, in which the wires run generally horizontally the two rollers may be brought to a condition where the common plane of their axes is vertical and the generally horizontal wire may be threaded through between the rollers in a straight line; but when the machine is to work, each of the pairs of rollers are brought to where their common plane is at an angle to the hoorizontal and are locked in that position so that each wire has to pass in a double bend around the pair of rollers.

We have found that the most advantageous surface for the rollers is a highly wear-resistant polyurethane. A stand supporting the rollers may also have a lateral spacing comb for receiving and guiding cords. Alternatively the comb may be spaced away from the rollers and be double-sided with teeth on the respective sides offset by the amount equal to the offset of lateral spacing means on the rollers whereby adjacent cords on the rollers are brought alternately to the two sides of the combs.

Particular forms of embodiment of the invention will now be described with reference to the accompanying drawings wherein:

FIG. 1 is a side elevation of the embodiment;

FIG. 2 is a front view of the embodiment, with part cut away;

FIG. 3 is a side view on a larger scale and showing an alternative lateral guide arrangement;

FIG. 4 is a plan view of part of tension control rollers; and

FIG. 5 is a diametrical section of a second form of roller.

In FIG. 1 we see a creel rack 1 of a Berstorff machine with a vertical array of'reels of wire made up of a plurality of rows 2 of reels. Each row 2 contributes a layer of wires to the embedding machine and there is in each row a number of reels corresponding to the number of wires in each layer. There may be a plurality of these vertical arrays arranged parallel to the one shown i.e., behind the plane of the paper as drawn in FIG. 1. One cord or wire is led from each reel and over a hardened steel rail 3 and wire path control roller 4, for each horizontal row 2. The reels may be individually braked only to the extent needed to prevent overrunning if the wires suddenly cease to be drawn off. The rail 3 is provided with hardened pins 5 so that it forms a gate or comb, for the initial lateral positioning and assembling of cords or wires from a given horizontal row. The roller 4 determines the horizontal level, and keeps wire clear of the gate rail 3, for the avoidance of wear. Instead of the wires being led directly from the creel rack to an embedding machine, tension controlling means are inserted in the path of the wires. These are shown on a tension control mounting stand 6 which may be mounted on the common frame with the creel rack or may be mounted in any suitable point in the wire path between the creel rack and the embedding machine. The stand 6 is optionally followed by a spearate comb stand 7, or (particularly when there is not a very large number of wires in each layer) by a guide comb mounted on the stand 6.

The tension control stand 6 has a plurality of pairs of tensioning roller devices generally designated 8 which will be described in more detail with reference to FIG. 3, and the comb stand 7 has a plurality of combs 9. As shown in FIG. 2, there is one device 8 on each side of stand 6 per horizontal layer of wires and there is one comb assembly 9 on each side of the comb stand 7 for each horizontal layer of cords or wires. Each device is common to any number of wires in this case approximately 100 wires.

As can be seen better in FIG. 3, the wires follow a path 10 after having left the path guide roller 4 and proceed under a first roller 11 of a tension control device 8. This has a pair of tension control rollers 11 and 12. The wire passes under and part way around the first roller 11 and then over and part way around the second roller 12, emerging in a path indicated at 13 in FIG. 3. In the form shown in FIG. 3, it is laterally guided and vertically restrained by an eyelet 14 which entraps it. In the form shown in FIG. 1 lateral guidance is given by the double sided combs of the comb assemblies 9. Wires are passed alternately to the upper and lower combs, of which the teeth are offset appropriately. In either case the wires then go to other guide arrangement, known per se, and then to the embedding machine.

The first roller 11 is mounted on a non-rotating shaft 15 borne at each end by swivelling arms 16 which can pivot about an axis defined by a shaft 17, about which the second roller 12 is free to rotate. In this way the first roller 11 may orbit around second roller 12, both rollers being free to rotate about their own axes defined by shafts l5 and 17 respectively. The shaping of the arms 16 is such that they offer a detent 19 for a latch arm 20 which is pivoted at 21 to the frame 6 at a level above that of the axis 17 and at a greater radius from it than any point of the roller 11. This means that if the latch arm 20 is released by being swung away from the detent 19 the swivel arms 16 may be brought to the dotdash line position 16 indicated in FIG. 3 so that the roller 11 is in the position 11. This position is defined by a stop pin 22 on the frame and the lowered position (full line position in the drawing) is defined by stop pin 23. The are through which the arm 16 common plane of the axes of rotation of the rollers can travel is about 120 i.e., from the vertical downwardly through the horizontal to below the horizontal.

Each roller 11, 12 has two sources of resistance to rotation. The first (which in some embodiments may be the sole one) is the radial bearing forces generated in the bearings of the roller when rotated under radial load. The second is a brake, in the present case a trimming friction brake in the form of a disc 25 or 26 respectively pressing against an end-face of the roller under the influence of a compression spring 27, 28 respectively and trapped between the disc and the arm 16 and surrounding the respective axles 15 and 17.This

effect may be made adjustable by changing the spring or the nature of the friction plates. The friction plates are restrained from rotation by engaging a flatformed in the shafts 15, 17 respectively.

Each roller 11, 12 is made up of an inner steel sleeve covered by grooved high abrasion resistant covering. High resistance to wear is very important, as is also uniformity of diameter in the grooves. Suitable covering materials are polyethers, polyesters, polycaprolactone or polycarbonate polyols reacted with tolylene 2,4-diisocyanate, diphenyl methane 4,4-di-isocyanate or naphthalene 1,5-di-isocyanate, or other suitable elastomeric materials. I

This system either in one shot, prepolymer or gum stock form may be compounded with fillers and plasticisers and either/or chain extended/cross linked with sulphur organic peroxides, aromatic or aliphatic amines or short chain aromatic or aliphatic glycols.

Specifically, for example, we may use the polyurethanes commercially available from Avon Rubber Company Limited, Melksham, England under the names Avon Millable Urethane 31 :X 2" or Avon Millable Urethane 31 X 8.

There are grooves 30 in each of the coverings. Each groove receives one wire of the layer and the spacing apart of the grooves is the same as the lateral spacing apart of the pins 5 of the rail 3 and of the guides 14; the

grooves may be formed by machining in a plain moulded cylinder of urethane material bonded onto the steel cylinder, or a grooved covering may be moulded,

or as illustrated in more detail in FIG. 5 the surface of the cylinder may be made up ofa large number of identical washers.

In the modified form of roller shown in FIG. 5, a grooved surface 31 is made up by mounting a large: number of identical polyurethane washers 32 on a steel sleeve 33 and compressing them between a circlip 34 at one end of the sleeve and a ring 35 threaded onto an externally screw-threaded end 36 of the sleeve 33.

Each washer has a generally rectangular-section annu-- lar body 37 and a square section annulus 38 projecting from its radially outer periphery and staggered to overhang one side face 39 of the body. When the washers are assembled together side by side the overhanging square section projection 38 covers the interface be- The double comb assembly 9 illustrated in FIG. 2 is not an essential part of theinvention and may be replaced by single comb assembly made up of the guides 14 illustrated in FIG. 3.

In contrast to prior art arrangements where tension was supplied by providing individual braking for each reel on the creel assembly, here a common braking force is supplied the wires in a layer by causing each wire to pass over and drive the two rollers 11' and 12 j I each of which is subjected to a braking force. Moreover because the arm 16 pivots (when the latch arm 20 is re- 9 leased) the rollers can be brought so that the common plane of their axes is vertical. This is illustrated in dot- V dash lines in FIG. 3 and in that condition wire can passed straight through between the two rollers without V any involved threading. To adopt the working position the arm 16 is simply swung down until it hits the limit pin 23 and is then latched. This is of great value when setting up one of the machines. A very large number of wires may be involved in the setting up operation and individual threading through the S-bend formed in the working condition of the tension control rollers would be very time-consuming.

The invention is applicable also to machines, or positions in machines, where the run of the wires in a layer is generally vertical. Then the inoperative position of the rollers is with the common plane of their axes horizontal and the working position is attained by bringing the arm 16 through the vertical to a position at an angle to the vertical.

It is not essential that every groove of a tensioning arrangement roller shall be occupied by a wire, but there must be enough wires to drive the rollers in rotation without slippage between wire and covering. As an indication, occupation of less than 30 percent of the grooves can be said to be undesirable.

The tensioning effect given by a pair of rollers is governed (all other things being constant) by the angle through which the wire path bends. Although this working angle is not adjustable in the present embodiment, devices with adjustable working angles lie within the invention.

1 claim:

1. In the combination of creel rack and a machine for drawing and embedding wire from wire storage reels in the creel rack to form a wire-reinforced fabric wherein there are means for exerting tension on the wires the improvement comprising a tensioning device placed in the wire path between the creel rack and the machine and tensioning in common a plurality of the wires, the tensioning device including a pair of spaced-apart grooved rollers each having an abrasion-resistant surface of uniform diameter in the grooves, the plurality of wires running around each roller on its surface over a part of the periphery thereof,-each of the wires occupying one groove, all the grooves of each roller respectively being constrained to rotate in common, such that the wires execute a double bend in their path and drive the rollers against their resistance to rotation without slippage between any wire and the rollers.

2. The improvement claimed in claim 1 wherein the abrasionresistant surface of each roller is of a polyurethane material.

3. The improvement claimed in claim 1 wherein a friction brake provides part of the said resistance to rotation.

4. The improvement claimed in claim 1 wherein a swivelling link maintains the axes of rotation of the rollers spaced apart by a fixed distance but permits rotation of the common plane to a working attitude of the rollers in which the wires execute the said double bend around them and an attitude for an inoperative condition of the rollers in which the wires may be passed freely and directly between them, the said rotation of the common plane being about an axis coaxial with that of one of the rollers.

5. The improvement claimed in claim 1 wherein the embedding machine is a Berstorff machine.

6. A tensioning apparatus for wire feed in the manufacture of wire-reinforced fabrics and for positioning in a wire path between a creel rack and an embedding machine which includes a. a stand b. a plurality of tensioning devices mounted on the stand, there being at least one tensioning device for respective arrays of wires c. each tensioning device having i. a pair of rollers, each roller having a wearresistant grooved surface the whole of which is constrained to rotate together about an axis of rotation of the roller ii. an axis of rotation of a first of the pair of rollers being stationary relative to the stand, and an axis of rotation of second of the pair of rollers being movable about the first in an arc of a circle of predetermined radius iii. the said radius being greater than the sum of the radii of the two rollers and the said axes of rotation being parallel whereby the rollers are spaced apart d. means on the stand defining limit positions of movement of the axis of the second roller about that of the first, one limit position being a working position and one an inoperative position, and

e. latch means capable of releasably maintaining the rollers in the working position.

7. The apparatus claimed in claim 6 wherein the grooved surfaces of the rollers are formed by the collocation of a plurality of identical washers secured together against relative rotation and each having at one lateral edge peripheral portion defining a groove base and a portion defining a groove ridge.

8. The apparatus claimed in claim 6 wherein each roller has a brake which consists of a friction disc, a spring resiliently urging the disc into frictional contact with an end face of the roller, and keying means constraining the disc against rotation relative to a shaft defining the axis about which the respective roller rotates.

9. The apparatus claimed in claim 6 wherein the arrays are horizontal arrays and the inoperative position of the rollers presents a clear horizontal path between the rollers.

10. The apparatus claimed in claim 6 wherein the latch means (e) is a strut pivotally mounted on the stand and releasably engageable with a bearing arm for the pair of rollers at a position adjacent the axis of rotation of the second roller of the pair of rollers to be placed in compression between the arm and the stand, to maintain the rollers in the working position.

11. The apparatus claimed in claim 6 wherein the apparatus (f) comprises additionally stationary lateral spacer means for defining inlet gates to respective grooves of one roller of the pair of rollers, a line through each respective gate and groove being perpendicular to the axis of rotation of the one roller. 

1. In the combination of creel rack and a machine for drawing and embedding wire from wire storage reels in the creel rack to form a wire-reinforced fabric wherein there are means for exerting tension on the wires the improvement comprising a tensioning device placed in the wire path between the creel rack and the machine and tensioning in common a plurality of the wires, the tensioning device including a pair of spaced-apart grooved rollers each having an abrasion-resistant surface of uniform diameter in the grooves, the plurality of wires running around each roller on its surface over a part of the periphery thereof, each of the wires occupying one groove, all the grooves of each roller respectively being constrained to rotate in common, such that the wires execute a double bend in their path and drive the rollers against their resistance to rotation without slippage between any wire and the rollers.
 2. The improvement claimed in claim 1 wherein the abrasion-resistant surface of each roller is of a polyurethane material.
 3. The improvement claimed in claim 1 wherein a friction brake provides part of the said resistance to rotation.
 4. The improvement claimed in claim 1 wherein a swivelling link maintains the axes of rotation of the rollers spaced apart by a fixed distance but permits rotation of the common plane to a working attitude of the rollers in which the wires execute the said double bend around them and an attitude for an inoperative condition of the rollers in which the wires may be passed freely and directly between them, the said rotation of the common plane being about an axis coaxial with that of one of the rollers.
 5. The improvement claimed in claim 1 wherein the embedding machine is a Berstorff machine.
 6. A tensioning apparatus for wire feed in the manufacture of wire-reinforced fabrics and for positioning in a wire path between a creel rack and an embedding machine which includes a. a stand b. a plurality of tensioning devices mounted on the stand, there being at least one tensioning device for respective arrays of wires c. each tensioning device having i. a pair of rollers, each roller having a wear-resistant grooved surface the whole of which is constrained to rotate together about an axis of rotation of the roller ii. an axis of rotation of a first of the pair of rollers being stationary relative to the stand, and an axis of rotation of second of the pair of rollers being movable about the first in an arc of a circle of predetermined radius iii. the said radius being greater than the sum of the radii of the two rollers and the said axes of rotation being parallel whereby the rollers are spaced apart d. means on the stand defining limit positions of movement of the axis of the second roller about that of the first, one limit position being a working position and one an inoperative position, and e. latch means capable of releasably maintaining the rollers in the working position.
 7. The apparatus claimed in claim 6 wherein the grooved surfaces of the rollers are formed by the collocation of a plurality of identical washers secured together against relative rotation and each having at one lateral edge peripheral portion defining a groove base and a portion defining a groove ridge.
 8. The apparatus claimed in claim 6 wherein each roller has a brake which consists of a friction disc, a spring resiliently urging the disc into frictional contact with an end face of the roller, and keying means constraining the disc against rotation relative to a shaft defining the axis about which the respective roller rotates.
 9. The apparatus claimed in claim 6 wherein the arrays are horizontal arrays and the inoperative Position of the rollers presents a clear horizontal path between the rollers.
 10. The apparatus claimed in claim 6 wherein the latch means (e) is a strut pivotally mounted on the stand and releasably engageable with a bearing arm for the pair of rollers at a position adjacent the axis of rotation of the second roller of the pair of rollers to be placed in compression between the arm and the stand, to maintain the rollers in the working position.
 11. The apparatus claimed in claim 6 wherein the apparatus (f) comprises additionally stationary lateral spacer means for defining inlet gates to respective grooves of one roller of the pair of rollers, a line through each respective gate and groove being perpendicular to the axis of rotation of the one roller. 